Analysis of glimepiride by using derivative UV spectrophotometric method

Comparative pharmacokinetic evaluation of glimepiride orodispersable and conventional tablets in rabbits

OBJECTIVES

Glimepiride Orodispersable Tablets (ODT) were prepared with the goal to have rapid onset of action and higher bioavailability with ease administration to individuals with swallowing difficulty to ameliorate patient compliance.

SIGNIFICANCE

Glimepiride is a contemporary hypoglycemic medication that belongs to the family of sulfonylurea derivatives. It is used in type 2 diabetes mellitus. Compliance adherence remains one of the limitations with the conventional drug delivery system especially in pediatric, geriatric, psychiatric, and traveling patients, for such population ODT provides a good alternate dosage form compared with Commercial Tablets.

METHOD

The Comparative in vivo pharmacokinetic parameters of the prepared ODT and conventional tablets (CT) were evaluated using an animal model. The plasma concentration of Glimepiride after oral administration of a single dose was determined at predetermined time intervals with HPLC. The pharmacokinetic parameters were calculated using PK Solutions 2.0 from Summit PK® software.

RESULTS

The Cmax obtained with ODT (22.08 µg/ml) was significantly (p = 0.006) high, a lower tmax of 3.0 hr was achieved with the orodispersable formulation of the drug. The ODT showed 104.34% relative bioavailability as compared to CT and left shift of tmax as well.

CONCLUSION

As per findings of the in vivo investigation, the Glimepiride ODT would be beneficial in terms of patient compliance, quick onset of action, and increased bioavailability.

Rapid RP-HPLC method for simultaneous estimation of metformin, pioglitazone, and glimepiride in human plasma

An isocratic reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed for rapid and simultaneous separation and estimation of 3 antidiabetic drugs, namely, metformin, pioglitazone, and glimepiride, in human plasma within 3 min. Separation was carried out on a MAGELLEN 5U C18 (5 μm, 150 mm × 4.60 mm) using a mobile phase of MeOH–0.025 M KH2PO4 adjusted to pH 3.20 using ortho-phosphoric acid (85:15, v/v) at ambient temperature. The flow rate was 1 mL/min, and the maximum absorption was measured at 235 nm. The retention time of metformin, pioglitazone, and glimepiride was noted to be 1.24, 2.32, and 2.77 min, respectively, indicating a very short analysis time compared to that of other reported methods. Also, limits of detection were reported to be 0.05, 0.26, and 0.10 μg/mL for metformin, pioglitazone, and glimepiride, respectively, showing a high degree of method sensitivity. The method was then validated according to the FDA guidelines for the determination of the three drugs clinically in human plasma, in particular, regarding pharmacokinetic and bioequivalence simulation studies.

Standard addition with internal standardisation as an alternative to using stable isotope labelled internal standards to correct for matrix effects-Comparison and validation using liquid chromatography-​tandem mass spectrometric assay of vitamin D

With mass spectrometric detection in liquid chromatography, co-eluting impurities affect the analyte response due to ion suppression/enhancement. Internal standard calibration method, using co-eluting stable isotope labelled analogue of each analyte as the internal standard, is the most appropriate technique available to correct for these matrix effects. However, this technique is not without drawbacks, proved to be expensive because separate internal standard for each analyte is required, and the labelled compounds are expensive or require synthesising. Traditionally, standard addition method has been used to overcome the matrix effects in atomic spectroscopy and was a well-established method. This paper proposes the same for mass spectrometric detection, and demonstrates that the results are comparable to those with the internal standard method using labelled analogues, for vitamin D assay. As conventional standard addition procedure does not address procedural errors, we propose the inclusion of an additional internal standard (not co-eluting). Recoveries determined on human serum samples show that the proposed method of standard addition yields more accurate results than the internal standardisation using stable isotope labelled analogues. The precision of the proposed method of standard addition is superior to the conventional standard addition method.

A rapid hydrophilic interaction liquid chromatographic determination of glimepiride in pharmaceutical formulations

Glimepiride is one of the most widely prescribed antidiabetic drugs and contains both hydrophobic and hydrophilic functional groups in its molecules, and thus could be analyzed by either reversed-phase high performance liquid chromatography (HPLC) or hydrophilic interaction liquid chromatography (HILIC). In the literature, however, only reversed-phase HPLC has been reported. In this study, a simple, rapid and accurate hydrophilic interaction liquid chromatographic method was developed for the determination of glimepiride in pharmaceutical formulations. The analytical method comprised a fast ultrasound-assisted extraction with acetonitrile as a solvent followed by HILIC separation and quantification using a Waters Spherisorb S5NH2 hydrophilic column with a mobile phase consisting of acetonitrile and aqueous acetate buffer (5.0 mM). The retention time of glimepiride increased slightly with decrease of mobile phase pH value from 6.8 to 5.8 and of acetonitrile content from 60% to 40%, indicating that both hydrophilic, ionic, and hydrophobic interactions were involved in the HILIC retention and elution mechanisms. Quantitation was carried out with a mobile phase of 40% acetonitrile and 60% aqueous acetate buffer (5.0 mM) at pH 6.3, by relating the peak area of glimepiride to that of the internal standard, with a detection limit of 15.0 μg/L. UV light absorption responses at 228 nm were linear over a wide concentration range from 50.0 μg/L to 6.00 mg/L. The recoveries of the standard added to pharmaceutical tablet samples were 99.4-103.0% for glimepiride, and the relative standard deviation for the analyte was less than 1.0%. This method has been successfully applied to determine the glimepiride contents in pharmaceutical formulations.

Development and validation of RP-HPLC method for glimepiride and its application for a novel self-nanoemulsifying powder (SNEP) formulation analysis and dissolution study

Background

There are many analytical methods available for estimation of glimepiride in biological samples and pharmaceutical preparations. To our knowledge, there is no specific reverse-phase high-performance liquid chromatography (RP-HPLC) method for estimation of glimepiride and its dissolution study in self-nanoemulsifying powder (SNEP) formulation.

Methods

A simple method was carried out on a 5-μm particle octadesyl silane (ODS) column (250 × 4.6 mm) with acetonitrile: 0.2 M phosphate buffer (pH = 7.4) 40:60 v/v as a mobile phase at a flow rate of 1 mL/min, and quantification was achieved at 228 nm using PDA detector.

Results

The correlation coefficient (r 2) was found to be 0.999 over the concentration range of 0.2 to 2 μg/mL for glimepiride. The method was validated for linearity, accuracy, and precision. The limit of detection and limit of quantification were found to be 0.38 and 1.17 μg/mL, respectively.

Conclusions

The proposed method was found to be simple, precise, suitable, and accurate for quantification of glimepiride as an alternative to the existing methods for the routine analysis of glimepiride in pharmaceutical formulations and in vitro dissolution studies.

Determination of a novel ACE inhibitor in the presence of alkaline and oxidative degradation products using smart spectrophotometric and chemometric methods

Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride (IMD) in the presence of both its alkaline (AKN) and oxidative (OXI) degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra (D4) which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor–ratio difference spectrophotometric one (DD–RD) by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method (DD–DR1) at 243.2 nm, while method D is the mean centering of ratio spectra (MCR) at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0–32.0 µg/mL. Methods E and F are principal component regression (PCR) and partial least-squares (PLS), respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

Combining the isoabsorptive point in the ratio spectrum and the smart ratio difference methods for a single step determination of compounds with overlapped spectra

A new method significantly advantageous over the conventional spectrophotometric methods regarding simplicity, minimal data processing and applicability was developed. The new method is based on the fact that isoabsorptive points whenever present in an absorption spectrum will be retained even after division by a one component as a divisor in the ratio spectrum, in addition to a smart modification of the conventional ratio derivative and ratio subtraction methods. This modified method though simpler, enabled wider range of applications. The proposed method was applied for the analysis of brimonidine and timolol in laboratory prepared mixtures with mean percentage recoveries 100.64 ± 1.10 and 100.96 ± 1.16, respectively, and in their pharmaceutical formulation with mean percentage recoveries 100.88 ± 0.34 and 100.84 ± 0.72, respectively. The suggested method was validated according to USP guidelines and can be applied for routine analysis in quality control laboratories.

A smart simple spectrophotometric method for simultaneous determination of binary mixtures

A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modification for the ratio subtraction method. This modification enabled wider range of application. The proposed ratio difference method was applied for the determination of brimonidine and timolol in laboratory prepared mixtures with mean percentage recoveries 100.40±2.29 and 101.23±1.30 respectively, and in their pharmaceutical formulation with mean percentage recoveries 101.08±0.44 and 100.66±0.52 respectively. The suggested ratio difference method was validated according to USP guidelines and can be applied for routine quality control testing.

Rapid and specific approach for direct measurement of glimepiride in human plasma by LC-ESI-MS-MS employing automated 96 well format: application to a bioequivalence study

A rapid liquid chromatographic method with electrospray ionization tandem mass spectrometric (LC-MS-MS) detection is developed and validated for quantification of glimepiride in heparinized human plasma. Plasma samples, without a drying and reconstitution step, are extracted by solid-phase extraction (SPE) and eluted with 0.9 mL of acetonitrile-methanol (1:1, v/v) containing 0.05% formic acid. The analyte and glimepiride d8 (internal standard, IS) are chromatographed on a C(18) column; the mobile phase is acetonitrile-2 mm ammonium formate (88:12, v/v), with the pH adjusted to 3.5 with formic acid, at a flow rate of 0.5 mL/min. The retention times of glimepiride and the IS are 0.93 min, and the runtime is 1.6 min per sample. Selected reaction monitoring of MH(+) at m/z 491.20 and 499.26 result in stable fragment ions with m/z 351.80 and 359.96 for glimepiride and the IS, respectively. The response was a linear function of the concentration in the range of 2.0-650.0 ng/mL, with r ≥ 0.9994. The recovery of glimepiride and the IS ranged from 81.91 to 83.36%. The assay has excellent characteristics and has been successfully used for the analysis of glimepiride in healthy human subjects in a bioequivalence study. It was well suited to clinical studies of the drug involving large numbers of samples.

Simultaneous determination of retinoic acid and hydroquinone in skin ointment using spectrophotometric technique (ratio difference method)

An innovative spectrophotometric method was developed for simultaneous determination of compounds with interfering spectra in binary mixtures without previous separation, showing significant advantages over the conventional methods regarding minimal data manipulation and applicability. The proposed method was applied for the determination of retinoic acid and hydroquinone in laboratory-prepared mixtures with mean percentage recoveries 100.13 ± 0.31 and 99.99 ± 0.04, respectively, and in their pharmaceutical formulation with mean percentage recoveries 100.13 ± 0.86 and 100.07 ± 0.58, respectively. The method was validated according to USP guidelines and can be applied for routine quality control testing.

Development and validation of a repharsed phase- HPLC method for simultaneous determination of rosiglitazone and glimepiride in combined dosage forms and human plasma

BACKGROUND

Rosiglitazone (ROZ) and glimepiride (GLM) are antidiabetic agents used in the treatment of type 2 diabetes mellitus. A survey of the literature reveals that only one spectrophotometric method has been reported for the simultaneous determination of ROS and GLM in pharmaceutical preparations. However the reported method suffers from the low sensitivity, for this reason, our target was to develop a simple sensitive HPLC method for the simultaneous determination of ROZ and GLM in their combined dosage forms and plasma.

RESULTS

A simple reversed phase high performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous determination of Rosiglitazone (ROS) and Glimepiride (GLM) in combined dosage forms and human plasma. The separation was achieved using a 150 mm × 4.6 mm i.d., 5 μm particle size Symmetry® C18 column. Mobile phase containing a mixture of acetonitrile and 0.02 M phosphate buffer of pH 5 (60: 40, V/V) was pumped at a flow rate of 1 mL/min. UV detection was performed at 235 nm using nicardipine as an internal standard. The method was validated for accuracy, precision, specificity, linearity, and sensitivity. The developed and validated method was successfully used for quantitative analysis of Avandaryl™ tablets. The chromatographic analysis time was approximately 7 min per sample with complete resolution of ROS (tR = 3.7 min.), GLM (tR = 4.66 min.), and nicardipine (tR, 6.37 min). Validation studieswas performed according to ICH Guidelines revealed that the proposed method is specific, rapid, reliable and reproducible. The calibration plots were linear over the concentration ranges 0.10-25 μg/mL and 0.125-12.5 μg/mL with LOD of 0.04 μg/mL for both compounds and limits of quantification 0.13 and 0.11 μg/mL for ROS and GLM respectively.

CONCLUSION

The suggested method was successfully applied for the simultaneous analysis of the studied drugs in their co-formulated tablets and human plasma. The mean percentage recoveries in Avandaryl™ tablets were 100.88 ± 1.14 and 100.31 ± 1.93 for ROS and GLM respectively. Statistical comparison of the results with those of the reference method revealed good agreement and proved that there were no significant difference in the accuracy and precision between the two methods respectively. The interference likely to be introduced from some co-administered drugs such as glibenclamide, gliclazide, metformine, pioglitazone and nateglinide was investigated.

An ultraviolet-spectrophotometric method for the determination of glimepiride in solid dosage forms

BACKGROUND

Considering the cost of acquiring a liquid chromatographic instrument in underdeveloped economies, the rising incidence of diabetes mellitus, the need to evaluate the quality performance of glimepiride generics, and the need for less toxic processes, this research is an imperative.

METHODS

The method was validated for linearity, recovery accuracy, intra- and inter-day precision, specificity in the presence of excipients, and inter-day stability under laboratory conditions. Student's t test at the 95% confidence limit was used for statistics.

RESULTS

Using 96% ethanol as solvent, a less toxic and cost-effective spectrophotometric method for the determination of glimepiride in solid dosage forms was developed and validated. The results of the validated parameters showed a λ(max) of 231 nm, linearity range of 0.5-22 μg/mL, precision with relative SD of <1.0%, recovery accuracy of 100.8%, regression equation of y = 45.741x + 0.0202, R(2) = 0.999, limit of detection of 0.35 μg/mL, and negligible interference from common excipients and colorants. The method was found to be accurate at the 95% confidence limit compared with the standard liquid chromatographic method with comparable reproducibility when used to assay the formulated products Amaryl(®) (sanofi-aventis, Paris, France) and Mepyril(®) (May & Baker Nigeria PLC, Ikeja, Nigeria). The results obtained for the validated parameters were within allowable limits.

CONCLUSION

This method is recommended for routine quality control analysis.

Stability-indicating methods for the determination of mosapride citrate in the presence of its degradation products according to ICH guidelines

In the present work, different spectrophotometric methods and one spectrofluorimetric method have been developed and validated for the determination of mosapride citrate in the presence of its acid-induced degradation products. The drug was subjected to stress stability study including acid, alkali, oxidative, photolytic, and thermal stress degradation. The developed spectrophotometric methods included the use of first order derivative ((1)D), derivative of ratio spectra ((1)DD), mean centring of ratio spectra (MC) and H-point standard additions (HPSAM) spectrophotometric methods. For (1)D method, the peaks amplitudes at 282.8 and 319.6 nm were measured, while for (1)DD method those at 308 nm and 323 nm were measured. Mean centring of ratio spectra method used the values at 317 nm for calibration, while for HPSAM the absorbance at 273 and 288.6 nm were used. These methods were successfully applied for determination of mosapride in the concentration range of 5-70 µg.ml(-1). The spectrofluorimetric method was based on measuring the native fluorescence of mosapride in 0.1 M NaOH using λ(excitation) 276 nm and λ(emission) 344 nm and 684 nm with linearity ranges of 50-3000 ng.ml(-1) and 50-9000 ng.ml(-1), respectively. All the developed methods were validated according to the International Conference on Harmonization (ICH) guidelines and were applied for bulk powder and dosage form. The results obtained were statistically compared to each other using one-way ANOVA testing.

Electrochemical study of glimepiride and its complexation with β-cyclodextrin

The electrochemical behavior of a hypoglycemic drug, glimepiride (GM), was studied at glassy carbon (GCE) and carbon paste (CPE) electrodes in phosphate buffer over the pH range of 2.7–11.7 using cyclic and differential pulse voltammetry. Oxidation of the drug was shown to be an irreversible and diffusion-controlled process. Using differential pulse voltammetry (DPV), the drug yielded a well-defined voltammetric peak in phosphate buffer pH 6.4 at +1.16 V and pH 7.0 at +1.07 V (vs Ag|AgCl) on glassy carbon and carbon paste electrodes, respectively. This process could be used to determine glimepiride concentrations in the range from 1.0 × 10–5 to 3.2 × 10–5 mol l–1 with a detection limit of 2.0 × 10–6 mol l–1 in case of the glassy carbon electrode and in the range of 2.0 × 10–6 to 1.5 × 10–5 mol l–1 with a detection limit of 7.5 × 10–7 mol l–1 in case of the carbon paste electrode. The method was successfully applied to the determination of the drug in a tablet dosage form. Next, the formation of an inclusion complex of glimepiride with β-cyclodextrin (β-CD) in phosphate buffer (pH 7.0):methanol (90:10 (v/v)) has been investigated by differential pulse voltammetry as well as UV spectrophotometry and its stability constant was determined by both methods to be 202.0 and 197.9 l mol–1, respectively.

Glimepiride

Glimepiride, which belongs to the sulfonylurea group, has been widely analyzed for its physical chemical properties including its crystallinity. Moreover, methods to quantify glimepiride and its impurities, either in pharmaceutical dosage form or in biological sample, have also been extensively developed and reported. This chapter extracts all information needed to give more perspective regarding to this substance.

Improved liquid chromatographic tandem mass spectrometric determination and pharmacokinetic study of glimepiride in human plasma

An improved liquid chromatographic tandem mass spectrometric method for the determination of glimepiride in human plasma has been developed and fully validated. The article describes in detail the bioanalytical procedure and summarizes the validation results obtained. The samples were extracted using liquid--liquid extraction with a mixture of 1-chlorobutane-isopropanol-ethyl acetate (88:2:10, v/v/v). The chromatographic separation was performed on a reversed-phase Hypersil ODScolumn (250 x 4.6 mm i.d.; 5 microm particle size) using a mobile phase consisting of formic acid 0.05 M-acetonitrile (28:72, v/v), pumped at a flow rate of 0.3 ml min(-1) heated to 25 degrees C. The analytes were detected using an API 3000 triple quadrupole mass spectrometer with positive electrospray ionization in multiple reaction monitoring mode. Tandem mass spectrometric detection enabled the quantitation of glimepiride down to 0.50 ng mL(-1). Calibration graphs were linear (r better than 0.998, n=1), in concentration range 0.50--1000 ng mL(-1), and the intra- and inter- day RSD values were less than 10.37 and 11.55% for glimepiride. The method was successfully applied to a kinetic study in order to assess the main pharmacokinetic parameters of glimepiride.

Recent Developments of Derivative Spectrophotometry and Their Analytical Applications

Articles about the development of derivative spectrophotometric methods and analytical applications of derivative spectrophotometry (DS) published in the last nine years (since 1994) are reviewed.

HPLC study of glimepiride under hydrolytic stress conditions

Glimepiride is a modern hypoglycaemic agent, which belongs to the group of sulfonylurea derivates. In this paper, simple, specific and accurate RP-HPLC method was developed in order to study decomposition of glimepiride under the hydrolytic stress conditions (acid, neutral, alkaline and oxidative). The best separation of glimepiride and its degradation products was achieved on reverse phase C18 column. The mobile phase was composed of acetonitrile-phosphate buffer (pH 3.5, 0.03 M) (48:52, v/v). Employing RP-HPLC method, five main degradation products were detected in the exposed samples. It was found that the susceptibility of glimepiride to hydrolytic decomposition increased in following manner: neutral condition < alkaline condition < acid condition < oxidative condition.

Inadvertent sulfonylurea overdosage and hypoglycemia in an elderly woman: failure of serum hypoglycemia screening

We report a case of an 82 year-old woman who had two episodes of documented hypoglycemia. Initial laboratory testing revealed hyperinsulinemia and a negative serum sulfonylurea screen. While these data suggested the presence of an insulinoma, further evaluation of the case revealed inadvertent ingestion of glimepiride, a sulfonylurea not included in the standard serum sulfonylurea screen.